trimming lemon tree
Hedging citrus is a common practice here in FL. Most people do it in early summer, but they do not chop the trees back so far that there are no leaves left. The idea is to make your tree a uniform shape so that there is more surface area exposed to the sun, and thus more space to bear fruit. They also top the trees which would help you reach the fruit easier. My reccomendation would be to cut the lemon tree just like you would a hedge, and try to shape it like a dome.
General advise for better health and bearing:
fertilize Feb (before bloom), June, and Sept
use oil spray during summer as needed